两者均有“债券”的含义。但覆盖范围不同。

bond为通用语，但与debenture（也称为debenture bond）在一起时多指具有抵押担保的“担保债券”﹔其偿还期限一般较长，常为国家或政府（包括外国）等机构发行。（debenture：a long-term, interest-bearing debt instrument issued by a corporation or governmental entity usu. to provide for a particular financial need; esp., such as instrument in which the debt is secured by a lien on the issuer’s property.” (Cf. Bryan A. Garner, Black’s Law Dictionary, 7th edition, at p.172, West Group (1999).

公司也可发行bond，如公司发行的债券是无担保或抵押的债券（unsecured bond）时其则被称为debenture（“Corporation bonds may be unsecured (debenture) or secured by the assets of the corporation”）。

由此可知，debenture是一种不具备抵押担保，属于无担保债务票据“unsecured debt instruments”之承诺债务的凭证，故有人也将其译为“信用债券”或“无抵押担保债券”。

在美国，debenture通常只能由三种公司发行（具有部分有形资产的服务公司“service corporation”、大的蓝筹码公司“large, blue-chip companies”、以其所有资产为按揭抵押之公司“corporations that have mortgaged all their available assets”);但有时debenture也可以由任何个人发行，故其不宜纯粹译为“公司债券”。debenture常可转换为公司的股票。

以下为相关双语示例，供参考：

Any debentures, bonds or other securities may be issued at a discount, premium or otherwise and with any special privileges as to redemption, surrender, drawings, allotment of shares, attending and voting at general meetings of the Company, appointment of Directors and otherwise. cre8ir.com

任何无抵押担保债券、债券或其他证券可按折让价、溢价或以其他方式发 行，并可附带有关赎回、交回、提取、配发股份、出席本公司股东大会并于 会上投票、委任董事及其他方面的任何特权。 

The Board may exercise all the powers of the Company to raise or borrow money and to mortgage or charge all or any part of the undertaking, property and assets (present and future) and uncalled capital of the Company and, subject to the Law, to issue debentures, bonds and other securities, whether outright or as collateral security for any debt, liability or obligation of the Company or of any third party. 

董事会可行使本公司一切权力筹集或借贷款项及将本公司全部或任何部分（现时及日后的）业务、物业及资产以及未催缴股本予以按揭或押记，并在公司法规限下，发行无抵押担保债券、债券及其他证券，不论是纯粹为此等证券而发行，或是作为本公司或任何第三方任何债项、债务或义务的保证而发行。